Jona's home is not on Nami Star, but on a planet nearby called Sky Dome Star. It is relatively small, only one-third the size of Nami Star, and it's a planet with very scarce water resources. Therefore, there are very few green spaces on the entire planet; most of it consists of mines and deserts...
What makes things worse is that, due to its proximity to the Main Star, the mining resources of Sky Dome Star are extremely convenient to transport after extraction. So even though there has been significant conservation efforts, after thousands of years of mining, the entire planet's mineral resources have nearly been exhausted, and most of the land is covered with yellow sand...
The depletion of resources also leads to a yearly decrease in the permanent population. Now, an enormous planet has a permanent population of less than 10 million, mostly the elderly, weak, sick, and disabled...
As for the young people?
